1. Field of the Invention
The present invention relates to a LED lamp, and in particular to a LED lamp uses liquid as thermal conductive medium.
2. Description of Prior Art
Light emitting diodes (LEDs) have the advantages of small volume, long lifetime, difficulty damage, without mercury and lower power consumption. They are gradually replacing the fluorescent tubes and incandescent lamps and widely used in indoor and outdoor lighting and decorative lighting.
However, in comparison to other lighting source, LEDs with higher power are more prone to a problem of heat dissipation. The main reason is that the heat of the LEDs cannot be dissipated through infrared radiation. Moreover, the multiple packages of the LEDs render junction thermal resistances at different junctions such that the LEDs cannot effectively dissipate heat. In general, over-temperature operation makes the LEDs reduce light output (light decay), color shift and accelerate aging to shorten the lifetime of the LEDs.
In order to solve the problems mentioned above, some manufacturers dispose fins on a housing of the LED lamp, or dispose a fan within the housing to enhance heat-dissipating capability of the LED lamp. However, the manufacturing method mentioned above enlarges the volume of the LED lamp and increase manufacturing procedures.